Many M1919s were rechambered for the new 7.62
Ч 51 mm NATO round and served into the 1990s, as well as up to the present
day in some countries. The United
States Navy also converted many to 7.62 mm NATO, and designated them Mk
21 Mod 0; they were commonly used on river craft in the 1960s and 1970s in
Vietnam.